Alternate light lighting fixture

ABSTRACT

A primary lamp and a spare standby lamp are interconnected in parallel with a source of electrical energy through an automatic lamp changing device in order to provide illumination from the standby lamp should there be burn out of the primary lamp. Lamp change-over operation is effected by momentarily switching off the lamp energizing circuit following burn out of the primary lamp and involves a single relay device connected in series with the standby lamp to maintain the same energized in a circuit parallel to that of the primary lamp when operating.

United States Patent 19 1 Alford, Jr. [4 1 July 23, 1974 4] ALTERNATELIGHT LIGHTING FIXTURE Primary Examiner-L. I-Iix [76]- lnventor: RickerAlford, .Ir., 2ll Murry Rd., g i" g Flrm clarence O Bnen;

West Palm Beach, Fla. 33405 vey 22 Filed: June 23, 1972 57] ABSTRACT[21] Appli No.: 241,803 I v v A primary lamp and a spare standby lampare intere connected in parallel with a source of electrical en- [52]US. Cl 307/157, 315/90, 3 15/93 erg), through automatic lamp Changingdevice in [51] IIIL CI. H02] order to provide illumination from hStandby p 531. Field of Search ..3l5/86 8, 7 should there .be burn outof the primary lamp. Lamp change-over operation is effected bymomentarily [56] Rdtrences C'ted switching off the lamp energizingcircuit following UNITED STATES PATENTS v burn out of the primary lampand involves a single 1,925,200 9/1933 Miller 315/93 relay deviceconnected in series with the standby lamp 3,197,674 7/1965 Hellman315/93 to maintain the same energized in a circuit parallel to glad? I ythat of the primary lamp when operating. v I I 2 Claims, 1 DrawingFigure P J I j y 2/ y of the burnt out lamp bulb.

ALTERNATE LIGHT LIGHTING FIXTURE This invention relates to a lampchange-over device wherein illumination is provided by a standby lampbulb whenever a primary lamp bulb burns out to thereby reduce thefrequency of manual replacement Automatic lamp changing devicesachieving the general purposes of thepresent invention, are well known.All of such lamp changing devices involve the switching of the powersource from the primary lamp to the standby lamp in response to burn outor failure of the primary lamp. Relay devices and associated switchingmechanism areaccordingly associated with such prior lamp changingdevices. Such prior lamp changing devices are however usually relativelycomplex or-involve power consuming relay componentsconnected in serieswith the lamps to thereby reduce the energy available for energizing thelampsand producing illumination. It is therefore an important object ofthe present invention to provide a lamp changing device which willautomatically turn on an alternate light in a new and useful manner. r

power line 1 is connected, and a normally open relay contact 7 connectedto the other terminal of the primary lamp 3 opposite the terminal towhich the power line 1 is connected. The normally open contact'7 is-alsoconnected to one terminal of the relay coil 8, the other "through therelay coil 8 in series with the primary lamp 3 resulting in energizationof the relay coil 8 and actuation of the relay switch 9. when relayswitch 9 is actuated, power is disconnected from the standby lamp and arelayholding circuit established through the normally open relay contact7 by connecting the relay coil 8 in series with the standby lamp 4across the power supply through the power lines 1 and 2. At the sametime, a lamp energizing circuit is completed by the relay switch Inaccordance with the presentinvention, an electri- The relay switch isaccordingly actuated so as to transfer power to the normally opencontact of the relay device to thereby complete a relay holding circuitthroughthe relay coil in series with the standby lamp and at the sametime connecting the primary lamp across the powersupply in bypassrelation to the relay coilv The primary lamp as well as the relay coilare thereby maintained energized as long as the primary lamp isin'operation. Thus, when-the primary lamp burns out, the relayenergizing circuit is interrupted by momentary interruption of thepowersupply. The energization of t he relay device-will then transfer powertothe standby lamp while re-energization of the relay-coil will beprevented in view of the burn out of the primary lamp.

These together with other objects and advantages which will becomesubsequently apparentreside in the details of construction-and operationas more fully hereinafter describedand claimed, reference being had tothe accompanying drawing forming a part hereof, wherein like numeralsrefer tolike parts throughout.

Referring now to the drawing in detail, a suitable power supply isconnected to the lamp changing system of the present invention throughpower lines 1 and 2 respectively extending from two power supplyterminals. Power line 1 is connected to both a primary lamp 3 and aspare standby lamp 4 which may be of-the incandescent' filament type asshown in the drawing. Power line 2 on the other hand is connected to asingle pole, double throw relay switch 9 associated with. a relay devicehaving a switch actuating relay solenoid or coil 8. Also associated withthe relay device, is a normally closed contact 6 connected to oneterminal of the standby lamp 4 opposite the terminal to which the 9 andnormally opencontact 7 through the primary lamp 3 in bypass relation tothe relay coil 8. Thus, the

' primary lamp 3 will be energized by means of a circuit lumina-tionwithout any voltage reducing load in series therewith as long as thestandby lamp filament is intact since it is int he circuit maintainingtherelay coil energized. If any open circuit occurs in the standby lamp,

the relay coil 8 will be, de-energized thereby also decircuit in orderto effect de-energization of the relay coil 8. When the power supply isconnected once again to the'power lines 1 and 2, the relay coil 8 willnot be energized because its circuit will be held open by the burnt outprimary lamp 3. The standby lamp will thereprinciples of the invention.Further, since numerous modifications and changes will readily occur tothose skilled in the art, it is not desired to limit the invention tothe exact construction and operation shown and described, andaccordingly all suitable modifications and equivalents may be resortedto, falling within the scope of the invention.

I claim:

1. lncombination with a source of electrical energy and a pair of lampsalternatively energized by said source for providing illumination,automatic lamp changing means comprising a relay device having a relaycoil, a relay switch actuated in response to energization of the relaycoil, a normally closed contact engaged by the relay switch and anormally open contact engageable by the relay switch when actuated, arelay energizing circuit connecting said relay coil to the source inseries with one of the lamps through the normally closed contact and therelay switch in engagement therewith, a lamp energizing circuitconnecting said one of the lamps to the source in by-pass relation tothe relay coil through the normally open contact and the actuated relayswitch in engagement therewith, and standby 'circuit means connectingthe other of the lamps to the source in parallel with the relay and lampenergizing circuits through the relay switch for alternativelymaintaining the relay coil and the other of the lamps energized wherebythe other of the lamps is maintained energized in response tode-energization of

1. In combination with a source of electrical energy and a pair of lampsalternatively energized by said source for providing illumination,automatic lamp changing means comprising a relay device having a relaycoil, a relay switch actuated in response to energization of the relaycoil, a normally closed contact engaged by the relay switch and anormally open contact engageable by the relay switch when actuated, arelay energizing circuit connecting said relay coil to the source inseries with one of the lamps through the normally closed contact and therelay switch in engagement thErewith, a lamp energizing circuitconnecting said one of the lamps to the source in by-pass relation tothe relay coil through the normally open contact and the actuated relayswitch in engagement therewith, and standby circuit means connecting theother of the lamps to the source in parallel with the relay and lampenergizing circuits through the relay switch for alternativelymaintaining the relay coil and the other of the lamps energized wherebythe other of the lamps is maintained energized in response tode-energization of the relay coil following burn out of said one of thelamps.
 2. The combination of claim 1 wherein said other of the lamps isconnected in series with the relay coil to the source by the standbycircuit means to maintain the relay coil energized, the relay coil beinginitially energized through the relay energizing circuit opened inresponse to actuation of the relay switch.